Association between prenatal maternal smoking and drinking and subtypes of ADHD

Prenatal maternal alcohol drinking and cigarette smoking have been postulated as risk factors for the development of ADHD symptoms in offspring. We used logistic regression to predict DSM4 and latent class (LC) ADHD subtypes based upon variables measuring alcohol and nicotine use during pregnancy and other potential risk factors. Our data consisted of a population sample of 2300 adolescent and young adult male twins and their siblings. Mothers completed an ADHD assessment for their offspring as well as reporting their own history of drinking and smoking prior to and during pregnancy. Analyses indicated that mothers of offspring with fewer ADHD symptoms reported less frequent cigarette and alcohol use during pregnancy than did mothers of offspring diagnosed with DSM ADHD. While both risk factors were predictive of the combined LC subtype, only smoking was associated with DSM combined type. Lower pre-pregnancy BMI (body mass index) and higher infant birth weight also predicted fewer ADHD symptoms in offspring, contrasted with the significant association of lower birth weight and higher BMI with the LC combined and inattention subtypes and the DSM inattention subtype. These results suggest the need to test for genotype by prenatal exposure interactions in genetic analysis of ADHD.